MPPT Dual Battery Solar controller

[TONCAZ]

Afternoon

Just purchased an MPPT controller for my new solar panel, is it worth fitting a Blocking Diode on the solar panel Pos leg?, also put my multimeter across the Neg terminal and had continuity across all Neg terminals, this is a dual battery controller so I think i could use a 2:5 mm 3 core flex from controller to 1st battery(1 neg 2 pos) then onto second battery, reason for this is the controller is on one side of motorhome and batts are on the other, about a 3m run.

Cheers

 

[I2C]

To answer your first question, your solar panel should already have a blocking diode, so no you don’t need one.

Don’t understand your second question I’m afraid.

Personally I’d move the controller next to the batteries, it shouldn’t really be 3 meters away.

 

[TONCAZ]

Cheers for that, as for the second part, I thought i could link the 2 neg outputs at the controller and just run one neg to 1st battery then onto the second, i understand you need 2 pos,
The location of controller will be the wardrobe, not really anywhere else to install it unless in goes under the lounge area seat with the MH battery.

Tony

 

[I2C]

My controller is under the lounge seat next to the leisure battery, less losses due to cable lengths.

Ok, no you can’t do what you’re talking about, that is if I’m right in assumimg you have two leisure batteries?

 

[Richard n Ann]

Cheers for that, as for the second part, I thought i could link the 2 neg outputs at the controller and just run one neg to 1st battery then onto the second, i understand you need 2 pos,
The location of controller will be the wardrobe, not really anywhere else to install it unless in goes under the lounge area seat with the MH battery.

Tony

Yes all negatives are common and on the vehicle chassis (earth too)
If you're just running one negative make it a thick one, I'd use 6mm cable for both.
Our Votronic doesn't even have a negative connection for the starter battery

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[TONCAZ]

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[TONCAZ]

My controller is under the lounge seat next to the leisure battery, less losses due to cable lengths.

Ok, no you can’t do what you’re talking about, that is if I’m right in assumimg you have two leisure batteries?

No just the one, was going to use the other out put for the starter batt, will run 2 cables from controller then install it in the MH batt area under the seat, to be honest didn't think that was too much of a run (live and learn)..

Tony

 

[I2C]

Ok, like Richard n Ann we have a Votronic charger, one negative to the leisure battery and the output for the starter battery from a different output on the charger.

 

[TONCAZ]

My controller is under the lounge seat next to the leisure battery, less losses due to cable lengths.

Ok, no you can’t do what you’re talking about, that is if I’m right in assumimg you have two leisure batteries?

No just the one, was going to use the other out put for the starter batt, will run 2 cables from controller then install it in the MH batt area under the seat, to be honest didn't think that was too much of a run (live and learn)..

Tony

 

[autorouter]

There will already be a good connection between the negatives of the leisure and starter batteries, capable of carrying at least the 30 or 40A from the alternator when the split charge relay is operating. It should be easily capable of carrying the couple of amps that the MPPT controller starter battery output usually supplies. So I'd say no extra negative wire is necessary for this.

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[mitzimad]

No just the one, was going to use the other out put for the starter batt, will run 2 cables from controller then install it in the MH batt area under the seat, to be honest didn't think that was too much of a run (live and learn)..

Tony

extend the solar cables and put the controller close to the batteries 2.5 flex isnt correctfor 12v
#

 

[TONCAZ]

extend the solar cables and put the controller close to the batteries 2.5 flex isnt correctfor 12v
#

Thanks for that, think I have some 4 or 6mm cable somewhere and install controller in the MH battery area under the seating/lounge area then its only a short hop the starter battery on a Burstner T700

Tony